(i) Field of the Invention
The present invention relates to a protease having a high activity at a low temperature and its utilization.
(ii) Description of the Related Art
Psychrophilic bacteria have been known for a long time, and their existence can be confirmed extensively in low temperature circumstances. For example, psychrophilic bacteria can be isolated from soils, fishery products, milk products as well as artificial low temperature circumstances. Researches on psychrophilic bacteria have been conducted in accordance with food microbiological requirements, but they have principally been confined to those with respect to the phylogeny of microorganisms.
Enzymes obtained from psychrophilic bacteria are expected to be cold-active is enzymes having an optimal temperature in a low temperature range. The cold-active enzyme which acts efficiently at the low temperature is considered to be capable of being incorporated into, for example, a detergent which can be used even in water at the low temperature. It is also considered to be employed for a chemical reaction in the presence of an organic solvent which is volatile at ordinary temperature and for the quality improvement of foods at the low temperature at which the foods do not rot. Furthermore, the investigation on the enzyme derived from the psychrophilic bacteria is fairly interesting to reveal the physiological functions and the adaptation mechanism to the low temperature of the psychrophilic bacteria.